The mood was described as “uniquely informal” but the stakes could not have been higher: at a landmark summit in the Californian desert, the leaders of the United States and China set out to show that “a rising power and existing power are not destined for conflict . . . that this is not an inexorable dynamic”.

Barack Obama and Xi Jinping took an unprecedented hour-long stroll, alone bar their translators, but the fruit of that quality time appeared mixed: a shared agenda on opposing North Korea’s pursuit of nuclear weapons emerged and there was progress on climate change, but divisions remained about Chinese cyber-espionage.

The White House had stressed that the “shirt-sleeves summit” at the Sunnylands estate near Palm Springs was not expected to